Concentric Annular Clearance-Controllable Pressure Characteristics Research of a High Pressure Pneumatic Pressure Assembly

High pressure is an important development orientation in pneumatic field,since it can not only improve dynamic characteristics of pneumatic system but also decrease the size of components and mounting space.Due to the advantages of high energy density and high instant expansibility,high pressure gas has been widely used in many applications.However,systematic researches are lacked especially in pressure characteristics which are very important in pneumatic system at present.In a high pressure pneumatic system,the pressure of a fixed cavity with annular clearance needs to be controlled within a wide range,so a single stage proportional slide valve is proposed to satisfy the requirements of high pressure and low flow rate.First,working principle and structure of the pressure assembly and the slide valve are introduced.Then mathematical model of the high pressure pneumatic system is built up;controllable pressure range is simulated,and influence of uncertain factors,such as fit clearance of the pressure valve and the cavity on controllable pressure,is discussed.Finally,a test bench of the pressure assembly is built up,and the controllable pressure and step response experiments are carried out.Both simulation and experimental results show that the designed slide valve can satisfy the requirements well.The proposed clearance presumption method based on simulation and experimental results is valuable for indirect measurement of processing tolerance.

Kinetic study on pressure leaching of high iron sphalerite concentrate

The kinetics of pressure leaching high iron sphalerite concentrate was studied.The effects of agitation rate,temperature, oxygen partial pressure,initial acid concentration,particle size,iron content in the concentrate and concentration of Fe2 +added into the solution on the leaching rate of zinc were examined.The experiment results indicate that if the agitation rate is greater than 600 r/min,its influence on Zn leaching rate is not substantial.A suitable rise in temperature can facilitate the leaching reaction,and the temperature should be controlled at 140-150℃.The increase trend of Zn leaching rate becomes slow when pressure is greater than 1.2 MPa,so the pressure is controlled at 1.2-1.4 MPa.Under the conditions of this study,Zn leaching rate decreases with a rise in the initial sulfuric acid concentration;and Zn leaching rate increases with a rise of iron content in the concentrate and Fe 2+ concentration in the solution.Moreover,the experiment demonstrates that the leaching process follows the surface chemical reaction control kinetic law of“shrinking of unreacted core”.The activation energy for pressure leaching high iron sphalerite concentrate is calculated,and a mathematical model for this pressure leaching is obtained.The model is promising to guide the practical operation of pressure leaching high iron sphalerite concentrate.

Application of High-pressure Flat Membranes in Coal Chemical Wastewater Treatment

In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the conditions of different concentrations of influent TDS,COD and silicon dioxide.The results showed that when the concentration of influent TDS was 35 000-55 000 mg/L,the economic benefit of high-pressure flat membrane operation was the best,and the concentration ratio of high-pressure flat membranes was stable,varying from 3.3 to 3.6.As the concentration of influent organic matter ranged from 100 to 1 800 mg/L,the removal rate of organic matter ranged from 60% to 79%.In addition,the retention rate of high-pressure flat membranes to silicon dioxide was more than 90%.

Mechanism of high pressure roll grinding on compression strength of oxidized hematite pellets

The mechanism of high pressure roll grinding on improvement of compression strength of oxidized hematite pellets was researched by considering their roasting properties. The results indicate that oxidized hematite pellets require higher preheating temperature and longer preheating time to attain required compression strength of pellets compared with the common magnetite oxidized pellets. It is found that when the hematite concentrates are pretreated by high pressure roll grinding （HPRG）, the compression strengths of preheated and roasted oxidized hematite pellets get improved even with lower preheating and roasting temperatures and shorter preheating and roasting time. The mechanism for HPRG to improve roasting properties of oxidized pellets were investigated and the cause mainly lies in the increase of micro-sized particles and the decrease of dispersion degree for hematite concentrates, which promotes the hematite concentrate particles to be compacted, the solid-phase crystallization, and finally the formation of Fe203 bonding bridges during subsequent high temperature roasting process.

Particle characteristics and rheological constitutive relations of high concentration red mud

Red mud has relatively small solid particles （d50= 13.02 μm） and will flow in paste form under high pressure during pipeline transport. Red mud belongs to a two-phase flow of materials with high viscosity and a high concentration of non-sedimentation, homogeneous solid-liquids. It is difficult to test its rheological properties under atmospheric pressure. Measurements such as rotational viscometry can not reflect the real state of the material when it is flowing in a pipe. Tested rheological parameters are somewhat higher than the actual values. In our investigation, grain shape, distinctive modality and grain size distribution of red mud were tested. Based on the principle of tube measurement, rheological experiments on red mud at different concentrations were carried out by using our independently developed tube-type pressure theology test facility, and obtained constitutive equations. We conclude that red mud behaves as non-Newtonian pseudo-plastic fluid in pipe flows. Its consistency and power-law indices vary considerably with different concentrations.

Theory and application of rock burst prevention using deep hole high pressure hydraulic fracturing

In order to analyze the mechanism of deep hole high pressure hydraulic fracturing, nonlinear dynamic theory, damage mechanics, elastic-plastic mechanics are used, and the law of crack propagation and stress transfer under two deep hole hydraulic fracturing in tectonic stress areas is studied using seepage-stress coupling models with RFPA simulation software. In addition, the effects of rock burst control are tested using multiple methods, either in the stress field or in the energy field. The research findings show that with two deep holes hydraulic fracturing in tectonic stress areas, the direction of the main crack propagation under shear-tensile stress is parallel to the greatest principal stress direction. High-pressure hydraulic fracturing water seepage can result in the destruction of the coal structure, while also weakening the physical and mechanical properties of coal and rock. Therefore the impact of high stress concentration in hazardous areas will level off, which has an effect on rock burst prevention and control in the region.

Diffusion coefficients of natural gas in foamy oil systems under high pressures

The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.

Effect of rock joints on lined rock caverns subjected to high internal gaspressure

The storage of hydrogen gas in lined rock caverns(LRCs)may enable the implementation of the firstlarge-scale fossil-free steelmaking process in Sweden,but filling such storage causes joints in the rockmass to open,concentrating strains in the lining.The structural interaction between the LRC componentsmust be able to reduce the strain concentration in the sealing steel lining;however,this interaction iscomplex and difficult to predict with analytical methods.In this paper,the strain concentration in LRCsfrom the opening of rock joints is studied using finite element(FE)analyses,where the large-and small-scale deformation behaviors of the LRC are coupled.The model also includes concrete crack initiation anddevelopment with increasing gas pressure and rock joint width.The interaction between the jointed rockmass and the reinforced concrete,the sliding layer,and the steel lining is demonstrated.The results showthat the rock mass quality and the spacing of the rock joints have the greatest influence on the straindistributions in the steel lining.The largest effect of rock joints on the maximum strains in the steellining was observed for geological conditions of“good”quality rock masses.

Modeling of fluid dynamics interacting with ductile fraction propagation in high pressure pipeline

This paper presents a computational model for the fluid dynamics in a fractured ductile pipe under high pressure. The pressure profile in front of the crack tip, which is the driving source of crack propagation, is computed using a nonlinear wave equation. The solution is coupled with a one dimensional choked flow analysis behind the crack. The simulation utilizes a high order optimized prefactored compact-finite volume method in space, and low dispersion and dissipation Runge-Kutta in time. As the pipe fractures the rapid depressurization take place inside the pipe and the propagation of the crack-induced waves strongly influences the outflow dynamics. Consistent with the experimental observation, the model predicts the expansion wave inside the pipe, and the reflection and outflow of the wave. The model also helps characterize the propagation of the crack dynamics and fluid flows around the tip of the crack.

Effects of high-pressure activated slightly acidic electrolyzed water on cleaning and sterilization of pig transfer vehicles

The establishment of biosafety system is of enormous importance to the livestock and poultry production in terms of mitigating the transmission of diseases and implementing regional prevention and control measures.However,the current sterilization technology presents several drawbacks,including time-consuming procedures,chemical residues,and challenges in treating the sewage after rinsing.In this study,a novel cleaning and sterilization method that combines slightly acidic electrolyzed water and high pressure water-jet was developed.An orthogonal test was conducted to examine the correlation between high-pressure conditions and the various non-structural parameters on the efficacy of sterilization rate.In a field test,the effectiveness of the technology in cleaning pig transfer vehicles was evaluated by the total plate count and variations of community composition.The findings revealed that the combination of process parameters,including an available chlorine concentration of 200 mg/L,rinsing pressure of 170 bar,rinsing duration of 10 s,and residence time of 15 min,resulted in a removal rate of colony concentration on the surface of pig transfer vehicles of(96.50±0.91)%.Moreover,it was demonstrated to effectively inhibit a variety of pathogenic bacteria.The innovative cleaning system has the potential to replace traditional methods and reduces pollution while saving time and labor.It introduces a novel approach for sterilization of transportation in livestock and poultry farms as well as the biosafety construction of the animal husbandry.

LC-MS/MS法同时测定人血浆中氯吡格雷及其羧酸代谢物的浓度

目的建立快速测定人血浆中氯吡格雷及其羧酸代谢物SR26334含量的LC-MS/MS法。方法乙醚-正己烷(4:1,V:V)2次液-液提取法(中性和酸化条件下),采用Teknokroma C_(18)色谱柱,以那格列奈和吡格列酮为内标,同时测定血浆中氯吡格雷和SR26334的浓度。流动相:甲醇-0.1%甲酸(80:20,V:V);流速:0.2mL·min^(-1);以多反应离子监测方式检测:氯吡格雷[M+H]^+,m/z 322.1→212.1;那格列奈[M+H]^+,m/z 318.3→166.2;氯吡格雷羧酸代谢物SR26334[M+H]^+,m/z 308.1→q98.1;吡格列酮[M+H]^+,m/z 357.2→134.2。结果氯吡格雷和内标那格列奈的保留时间分别在4.4和3.7min,SR26334和内标吡格列酮的保留时间分别在1.3和1.7min,氯吡格雷的线性范围为5～5000ng·L^(-1);SR26334的线性范围为20～2500μg·L^(-1)。提取回收率大于75%,方法回收率大于90%,日内、日间RSD小于10%(n=5)。结论本方法简便快速,适用于氧吡格雷制剂的新药临床研究和临床长期治疗病人血药浓度的常规监测。

湖南某难处理金矿的加压预氧化-氰化浸金试验研究

针对湖南某难处理金精矿进行预处理技术研究.该矿含砷(质量分数)为11.28%,金的直接氰化浸出率为21.91%.矿石中的砷以毒砂形式存在.载金矿物为毒砂和黄铁矿等硫化物,金为微细浸染型被毒砂和黄铁矿包裹.通过加压预氧化,对矿石进行氰化浸金试验研究.加压氧化最佳条件为初始酸度1 mol/L,木质素磺酸钠5 g/t,硝酸硫酸比7∶1,氧压0.6 MPa,搅拌速度300 r/min,时间100 min,温度100℃,矿浆浓度20%.试验表明经过加压试验后,金的氰化浸出率达到90.87%,与未预处理相比提高了68.96%,达到了较好的试验效果.

用HPLC-MS/MS法测定人血浆中的二甲双胍浓度

目的：建立高效液相色谱-质谱／质谱（HPLCMS／MS）联用法测定人血浆中二甲双胍浓度的方法。方法：血浆样品经乙腈沉淀蛋白质后，用HPLC—MS／MS法测定二甲双胍浓度。甲醇-乙腈10mmol／L乙酸铵溶液（20：20：60）为流动相，流速为0．2mL／min；采用大气压化学电离源，以多离子反应监测（MRM）方式进行正离子检测，二甲双胍和内标苯乙双胍的定量分析离子对分别为m／z 130．2→71．0和m／z 206．1→59．9。结果：血浆样品中二甲双胍线性范围为2．0～2000μg／L（n=7，r=0．9996），最低定量限为2．0μg／L。低、中、高（10、500、1500 μg／L）3种浓度的日内RSD分别为4．65％、2．84％和3．41％（n=5）；日间RSD分别为7．96％、3．98％和4．77%（n=5）；准确度为95．9％、97．4％和89．90%（n=5）。结论：本方法灵敏度高、专属性强、重现性好、准确，可用于人血浆中二甲双胍的含量测定。

用液相色谱-质谱-质谱法测定人血清中非洛地平浓度

目的:建立液相色谱-质谱-质谱(LC-MS-MS)法测定人血清中非洛地平的浓度。方法:血清样品经液-液萃取预处理。色谱柱为Xterra柱(50 mm×2.1 mm,3.5μm),流动相为乙腈-0.02%氨水,采用梯度洗脱,流速为0.3 mL/min。非洛地平和尼莫地平(内标)的多反应监测(MRM)扫描离子对分别为m/z382.1→145和m/z417.2→92,两者的保留时间分别为1.24 min和1.06 min。结果:非洛地平在0.04～20 ng/mL范围内线性关系良好(r=0.999 7),低、中、高浓度(0.08、8.0、16.0 ng/mL)的日内RSD分别为6.60%、7.22%和5.01%(n=6),日间RSD分别为9.42%、8.46%和5.12%(n=14),准确度为98.21%～106.20%(n=6)。结论:本法操作简便,检测准确、灵敏、专一,重复性好,适用于非洛地平血药浓度监测和药动学及生物利用度研究。

用RP-HPLC法同时测定拉莫三嗪和奥卡西平的血药浓度

目的：用RP-HPLC法同时测定人血浆中抗癫药拉莫三嗪和奥卡西平的浓度。方法：以艾司唑仑为内标,色谱柱为Agilent Zorbax XDB-C18柱（150 mm×4.6 mm,5μm）;流动相为甲醇-0.1%三氟乙酸（38∶62）;流速为1.0 mL/min;检测波长为240 nm。结果：拉莫三嗪和奥卡西平的血药浓度分别在1.00-50.00μg/mL（Y=0.214 6c-0.010 9,r=0.999 4）和0.50-50.00μg/mL（Y=0.396 6c＋0.006 1,r=0.999 1）范围内线性良好;平均回收率分别为97.64%和97.67%（n=5）。拉莫三嗪2.5、10.0和40.0μg/mL的日内RSD分别为4.6%、3.7%和2.8%（n=5）,日间RSD分别为5.9%、6.4%和4.8%（n=5）;奥卡西平1.0、10.0和40.0μg/mL的日内RSD分别为3.6%、3.4%和4.0%（n=5）,日间RSD分别为5.5%、3.7%和4.3%（n=5）。结论：本方法操作简单,回收率高,精密度好,适用于临床上常规监测拉莫三嗪和奥卡西平的血药浓度。

HPLC-MS法测定人血浆中依普利酮浓度

目的:建立人血浆中依普利酮浓度的HPLC-MS测定法.方法:血浆样品中加入内标溶液后,以液-液萃取方法进行样品处理,采用HPLC-MS方法测定其血药浓度.结果:标准曲线线性范围为2.080～4160μg/L,标准曲线线性关系良好,回归方程为:f=0.0005520+0.001333×C(r=0.9984).高、中、低3浓度的批内和批间变异均小于15%,提取回收率在73.6%～75.5%.结论:建立人血浆中依普利酮浓度的HPLC-MS测定法操作简便,灵敏度高,适用于依普利酮的血药浓度检测及药动学研究.

RP-HPLC法测定法罗培南血药浓度和尿药浓度

目的：建立测定法罗培南血药浓度和尿药浓度的RP-HPLC法。方法：采用Diamond C18色谱柱（250mm×4．6mm，5μm），血样与尿样测定流动相分别为0．02mol／L磷酸二氢钾缓冲液（pH=2．95）：乙腈=75：25和81：19，流速均为1．0mL／min，检测波长均为318nm。结果：血浆样品的线性范围为0．03125～2．5μg／mL（r=0．9999）、2．5～120μg／mL（r=0．9997），最低检测浓度为31．25ng／mL，绝对回收率为68．9％～77．8％；尿液样品的线性范围为0．5～20μg／mL（r=0．9999）、20～1600μg／mL（r=0．9997），最低检测浓度为0．5μg／mL，绝对回收率为96．5％～106．0％。日内及日间精密度均〈11．0％。结论：本方法简单、快速，灵敏度和准确度较高，能满足法罗培南钠注射液临床药动学研究的需要。

用RP-HPLC法测定人血浆中巴洛沙星浓度并应用于治疗药物监测

目的：建立巴洛沙星血药浓度的RP-HPLC测定方法，并用于巴洛沙星片剂的药动学参数测定，为临床合理用药提供参考。方法：色谱柱为Diamonsil ODS C18柱（150mm×4．6mm，5μm），流动相为乙腈-水（含0．04mol／L磷酸和0．4％三乙胺，pH=4．5）=23：77，流速为1．0mL／min，柱温35℃，检测波长294nm。内标物为加替沙星。将该方法用于单剂量口服100mg巴洛沙星片的主要药动学参数研究。结果：该方法的线性范围为0．05～5．00μg／mL（r=0．9998），方法的日内及日间RSD〈10％。结论：该方法准确、快速、简便，可为临床评价药物治疗效果提供参考。

掺硫LEC-GaP单晶载流子的分布

采用高压液封直拉法生长2英寸N型掺硫GaP单晶,通过浮舟技术控制直径.按照理论公式计算出掺杂量,采用范德堡法测试掺硫GaP单晶头部、中部和尾部的载流子浓度.分析了固液界面形状对载流子分布的影响,在平坦的固液界面下得到的单晶载流子分布更为均匀.探讨了浮舟控径单晶横向和纵向载流子分布及其影响因素.比较和讨论了浮舟控径和无舟计算机闭环控径单晶纵向载流子分布,表明采用浮舟控制及工艺,造成晶体生长过程中分凝系数及补偿度的变化,使得晶体纵向载流子浓度先降低后升高,提出了通过变速拉晶,可以改善单晶纵向载流子均匀性.讨论了浮舟质量对载流子分布的影响,采用质量较大的浮舟生长GaP单晶,其纵向载流子分布更均匀.

云南某高硫难处理金精矿碱性加压预氧化-氰化浸金试验研究

对云南某高硫难处理金精矿进行碱性加压氧化—氰化浸金试验研究,考察了加压氧化各因素对氰化浸金的影响,在固液比1∶6、木质素磺酸钠5 g/t、Na OH用量25%、温度180℃、压力2.0 MPa、反应时间4h、搅拌转速450 r/min的加压氧化最优条件下获得了93.2%的较高金浸出率。